Lotsa undo stuff added;

- ALT+U undo menu shows history for global undo as well
- Added undo pushes for buttons window more consistantly
- Added it & tested for ipowindow too
- Added it in outliner
- And quite some missing occasions for 3d window editing

source/blender/src/interface.c

@@ -3250,10 +3250,19 @@ static int ui_do_block(uiBlock *block, uiEvent *uevent)
 					if(inside || uevent->event!=LEFTMOUSE) {
 						butevent= ui_do_button(block, but, uevent);
 						
-						if( !(block->flag & UI_BLOCK_LOOP))
-							if(but->type!=BLOCK && but->type!=MENU) 
-								if(!G.obedit)
-									BIF_undo_push(but->str);
+						/* add undo pushes if... */
+						if( !(block->flag & UI_BLOCK_LOOP)) {
+							if(!G.obedit) {
+								if ELEM4(but->type, BLOCK, BUT, LABEL, PULLDOWN); 
+								else {
+									/* define which string to use for undo */
+									if ELEM(but->type, LINK, INLINK) BIF_undo_push("Add button link");
+									else if ELEM(but->type, MENU, ICONTEXTROW) BIF_undo_push(but->drawstr);
+									else if(but->str[0]) BIF_undo_push(but->str);
+									else BIF_undo_push(but->tip);
+								}
+							}
+						}
 				
 						if(butevent) addqueue(block->winq, UI_BUT_EVENT, (short)butevent);